I don't think people would necessarily leave their wives for a robot but statistically, most marriages fail and after the very, very expensive failure, most men come back on the market in their 50s, with their finances capped by half and usually very bitter.

in this case, i could see them going full robot, since presumably the robot could also cook and do all kinds of stuff.

if they do ever make super realistic ones, i bet they will have a subscription model too, have to lease one! black mirror should really do an episode on this lol